High-pitch spiral acquisition: A new scan mode for coronary CT angiography

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• 作者：Stephan Achenbach ; MD^a ; ^{stephan.achenbach@uk-erlangen.de} ; Mohamed Marwan ; MD^a ; Tiziano Schepis ; MD^a ; Tobias Pflederer ; MD^a ; Herbert Bruder ; PhD^b ; Thomas Allmendinger ; PhD^b ; Martin Petersilka ; PhD^b ; Katharina Anders ; MD^c ; Michael Lell ; MD^c ; Axel Kuettner ; MD^c ; Dieter Ropers ; MD^a ; Werner G. Daniel ; MD^a ; Thomas Flohr ; PhD^b ; ^d
• 关键词：Computed tomography ; Coronary CT angiography ; Dual-source CT ; Radiation exposure
• 刊名：Journal of Cardiovascular Computed Tomography
• 出版年：2009
• 出版时间：March-April 2009
• 年：2009
• 卷：3
• 期：2
• 页码：117-121
• 全文大小：695 K

文摘

Coronary CT angiography allows high-quality imaging of the coronary arteries when state-of-the-art CT systems are used. However, radiation exposure has been a concern. We describe a new scan mode that uses a very high-pitch spiral acquisition, ¡°Flash Spiral,?which has been developed specifically for low-dose imaging with dual-source CT. The scan mode uses a pitch of 3.2 to acquire a spiral CT data set, while covering the entire volume of the heart in one cardiac cycle. Data acquisition is prospectively triggered by the electrocardiogram and starts in late systole to be completed within one cardiac cycle. Images are reconstructed with a temporal resolution that corresponds to one-quarter of the gantry rotation time. Throughout the data set, subsequent images are reconstructed at later time instants in the cardiac cycle. In a patient with a heart rate of 49 beats/min, the Flash Spiral scan mode was used with a first-generation dual-source CT system and allowed artifact-free visualization of the coronary arteries with a radiation exposure of 1.7 mSv for a 12-cm scan range at 120 kVp tube voltage.